Methods of skin rejuvenation using high intensity focused ultrasound to form an ablated tissue area containing a plurality of lesions

ABSTRACT

A method of skin rejuvenation by thermal ablation using high intensity focused ultrasound energy includes the steps of positioning an ultrasound emitting member adjacent an external surface of the skin, emitting ultrasound energy from the ultrasound emitting member into the skin, focusing the ultrasound energy in the skin, ablating the skin with the focused ultrasound energy to form an ablated tissue area below the external surface of the skin containing unablated tissue of the skin and a plurality of lesions at which the tissue of the skin is ablated, and removing the ultrasound emitting member from adjacent the external surface of the skin. The lesions cause collagen production by the skin to be stimulated. The lesions can begin and end at predetermined depths beneath the external surface of the skin so that the epidermis and the deep layer of the dermis are not damaged.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a continuation-in-part of prior U.S. patentapplication Ser. No. 09/487,705 filed Jan. 19, 2000 now abandoned, thedisclosure of which is incorporated herein by reference.

This application is related to U.S. patent applications Ser. No.09/487,708 filed Jan. 19, 2000 now abandoned, and entitled Methods ofSoft Palate Reduction By Thermal Ablation Using High Intensity FocusedUltrasound, Ser. No. 09/487,707 filed Jan. 19, 2000 and entitled Methodsof Tongue Reduction By Thermal Ablation Using High Intensity FocusedUltrasound now U.S. Pat. No. 6,413,254 issued Jul. 2, 2002, Ser. No.09/487,709 filed Jan. 19, 2000 and entitled Methods of Tonsil ReductionBy Thermal Ablation Using High Intensity Focused Ultrasound nowabandoned, Ser. No. 09/487,706 filed Jan. 19, 2000 and entitled Methodsof Turbinate Or Other Soft Tissue Reduction By Thermal Ablation UsingHigh Intensity Focused Ultrasound now abandoned, Ser. No. 09/488,844filed Jan. 21, 2000 and entitled Focused Ultrasound Ablation DevicesHaving Malleable Handle Shafts and Methods of Using the Same now U.S.Pat. No. 6,361,531 issued Mar. 26, 2002, and Ser. No. 09/487,710 filedJan. 19, 2000 and entitled Focused Ultrasound Ablation Devices HavingSelectively Actuatable Ultrasound Emitting Elements and Methods of Usingthe Same, the disclosures of which are incorporated herein by reference.

This application is also related to co-pending U.S. patent applicationsentitled Methods of Soft Palate Reduction Using High Intensity FocusedUltrasound To Form An Ablated Tissue Area Containing A Plurality ofLesions, Methods of Tongue Reduction Using High Intensity FocusedUltrasound To Form An Ablated Tissue Area Containing A Plurality ofLesions, Methods of Tonsil Reduction Using High Intensity FocusedUltrasound To Form An Ablated Tissue Area Containing A Plurality ofLesions and Methods of Turbinate Or Other Soft Tissue Reduction UsingHigh Intensity Focused Ultrasound To Form An Ablated Tissue AreaContaining A Plurality of Lesions, the disclosures of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the treatment of anatomicaltissue of the head and/or neck with high intensity focused ultrasoundenergy and, more particularly, to skin rejuvenation by thermalstimulation using high intensity focused ultrasound.

2. Brief Description of the Related Art

When high intensity ultrasound energy is applied to anatomical tissue,significant physiological effects may be produced in the anatomicaltissue resulting from thermal and/or mechanical changes or effects inthe tissue. Thermal effects include heating of the anatomical tissue;and, when the tissue is heated to a sufficiently high temperature,tissue damage such as coagulative necrosis is produced. In order toproduce thermal effects in anatomical tissue, ultrasound emittingmembers such as transducers have been used to emit ultrasound energywhich is applied to anatomical tissue by positioning the ultrasoundemitting members adjacent or in contact with the tissue or by couplingthe ultrasound emitting members to the tissue via an acoustic couplingmedium. By focusing the ultrasound energy at one or more specificfocusing zones within the tissue, thermal effects can be confined to adefined location, region, volume or area, and such location, region,volume or area can be remote from the ultrasound emitting member.

With the use of high intensity focused ultrasound (HIFU), one or morefocusing zones at or within a designated target location, region, volumeor area within a larger mass, body or area of anatomical tissue can besubjected to high intensity ultrasound energy while tissue surroundingthe target area is subjected to much lower intensity ultrasound energy.In this manner, tissue in the target area can be heated to asufficiently high temperature so as to cause a desired thermal effectsuch as tissue damage, ablation, coagulation, denaturation, destructionor necrosis while tissue surrounding the target area is not heated todamaging temperatures and, therefore, is preserved. Heating of tissue ina target location, volume, region or area to an ablative temperaturecreates an ablative lesion in the tissue in the target location, volume,region or area that is desirable in the treatment of various medicalconditions, disorders or diseases. For example, the lesion may remain astissue having altered characteristics or may be naturally degraded andabsorbed by the patient's body and thusly eliminated such that theremaining body, mass or area of tissue is of smaller volume or size dueto the absence of the ablated tissue.

The use of high intensity focused ultrasound to eliminate tissue or toalter the characteristics of tissue in a target location, volume, regionor area within a larger mass, body or area of anatomical tissue presentsmany advantages including minimization of trauma and pain for thepatient, elimination of the need for a surgical incision, stitches andexposure of internal tissue, avoidance of damage to tissue other thanthat which is to be treated, altered or removed, lack of a harmfulcumulative effect from the ultrasound energy on the surroundingnon-target tissue, reduction in treatment costs, elimination of the needin many cases for general anesthesia, reduction of the risk of infectionand other complications, avoidance of blood loss, and the ability forhigh intensity focused ultrasound procedures to be performed innon-hospital sites and/or on an out-patient basis.

Various devices and/or methods for treating anatomical tissue withultrasound have been proposed as represented by U.S. Pat. No. Re. 33,590to Dory, U.S. Pat. No. 3,990,452 to Murry et al, U.S. Pat. No. 4,658,828to Dory, U.S. Pat. No. 4,807,633 to Fry, U.S. Pat. No. 4,858,613 to Fryet al, U.S. Pat. No. 4,951,653 to Fry et al, U.S. Pat. No. 4,955,365 toFry et al, U.S. Pat. No. 5,033,456 to Pell et al, U.S. Pat. No.5,036,855 to Fry et al, U.S. Pat. No. 5,054,470 to Fry et al, U.S. Pat.No. 5,065,761 to Pell, U.S. Pat. No. 5,080,101 to Dory, U.S. Pat. No.5,080,102 to Dory, U.S. Pat. No. 5,117,832 to Sanghvi et al, U.S. Pat.No. 5,134,988 to Pell et al, U.S. Pat. No. 5,143,074 to Dory, U.S. Pat.No. 5,150,711 to Dory, No. 5,150,712 to Dory, U.S. Pat. No. 5,158,070 toDory, U.S. Pat. No. 5,222,501 to Ideker et al, U.S. Pat. No. 5,267,954to Nita, U.S. Pat. No. 5,269,291 to Carter, U.S. Pat. No. 5,269,297 toWeng et al, U.S. Pat. No. 5,295,484 to Marcus et al, U.S. Pat. No.5,304,115 to Pflueger et al, U.S. Pat. No. 5,312,328 to Nita et al, U.S.Pat. No. 5,318,014 to Carter, U.S. Pat. No. 5,342,292 to Nita et al,U.S. Pat. No. 5,354,258 to Dory, U.S. Pat. No. 5,380,274 to Nita, U.S.Pat. No. 5,391,197 to Burdette et al, U.S. Pat. No. 5,397,301 toPflueger et al, U.S. Pat. No. 5,409,002 to Pell, U.S. Pat. No. 5,417,672to Nita et al, U.S. Pat. No. 5,431,621 to Dory, U.S. Pat. No. 5,431,663to Carter, U.S. Pat. No. 5,447,509 to Mills et al, U.S. Pat. No.5,474,530 to Passafaro et al, U.S. Pat. No. 5,492,126 to Hennige et al,U.S. Pat. No. 5,501,655 to Rolt et al, U.S. Pat. No. 5,520,188 toHennige et al, U.S. Pat. No. 5,542,917 to Nita et al, U.S. Pat. No.5,620,479 to Diederich, U.S. Pat. No. 5,676,692 to Sanghvi et al, U.S.Pat. No. 5,728,094 to Edwards, U.S. Pat. No. 5,730,719 to Edwards, U.S.Pat. No. 5,733,315 to Burdette et al, U.S. Pat. No. 5,735,280 to Shermanet al, U.S. Pat. No. 5,738,114 to Edwards, U.S. Pat. No. 5,746,224 toEdwards, U.S. Pat. No. 5,762,066 to Law et al, U.S. Pat. No. 5,800,379to Edwards, U.S. Pat. No. 5,800,429 to Edwards, U.S. Pat. No. 5,800,482to Pomeranz et al, U.S. Pat. No. 5,807,308 to Edwards, U.S. Pat. No.5,817,049 to Edwards, U.S. Pat. No. 5,823,197 to Edwards, U.S. Pat. No.5,827,277 to Edwards, U.S. Pat. No. 5,843,077 to Edwards, U.S. Pat. No.5,871, 524 to Knowlton, U.S. Pat. No. 5,873,845 to Cline et al, U.S.Pat. No. 5,873,902 to Sanghvi et al, U.S. Pat. No. 5,879,349 to Edwards,U.S. Pat. No. 5,882,302 to Driscoll, Jr. et al, U.S. Pat. No. 5,895,356to Andrus et al, U.S. Pat. No. 5,928,169 to Schätzle et al and U.S. Pat.No. 5,938,608 to Bieger et al.

In particular, the use of high intensity focused ultrasound to thermallydamage, ablate, coagulate, denature, cauterize, necrotize or destroy atarget volume of tissue is exemplified by U.S. Pat. No. Re. 33,590 toDory, U.S. Pat. No. 4,658,828 to Dory, U.S. Pat. No. 4,807,633 to Fry,U.S. Pat. No. 4,858,613 to Fry et al, U.S. Pat. No. 4,951,653 to Fry etal, U.S. Pat. No. 4,955,365 to Fry et al, U.S. Pat. No. 5,036,855 to Fryet al, U.S. Pat. No. 5,054,470 to Fry et al, U.S. Pat. No. 5,080,101 toDory, U.S. Pat. No. 5,080,102 to Dory, U.S. Pat. No. 5,117,832 toSanghvi et al, U.S. Pat. No. 5,143,074 to Dory, U.S. Pat. No. 5,150,711to Dory, U.S. Pat. No. 5,150,712 to Dory, U.S. Pat. No. 5,295,484 toMarcus et al, U.S. Pat. No. 5,354,258 to Dory, U.S. Pat. No. 5,391,197to Burdette et al, U.S. Pat. No. 5,431,621 to Dory, U.S. Pat. No.5,492,126 to Hennige et al, U.S. Pat. No. 5,501,655 to Rolt et al, U.S.Pat. No. 5,520,188 to Hennige et al, U.S. Pat. No. 5,676,692 to Sanghviet al, U.S. Pat. No. 5,733,315 to Burdette et al, U.S. Pat. No.5,762,066 to Law et al, U.S. Pat. No. 5,871,524 to Knowlton, U.S. Pat.No. 5,873,845 to Cline et al, U.S. Pat. No. 5,873,902 to Sanghvi et al,U.S. Pat. No. 5,882,302 to Driscoll, Jr. et al, U.S. Pat. No. 5,895,356to Andrus et al, U.S. Pat. No. 5,928,169 to Schätzle et al and U.S. Pat.No. 5,938,608 to Bieger et al.

The skin is the largest organ of the body and is highly vulnerable todeterioration due to natural aging and/or exposure to environmentalconditions such as sun, wind, heat and cold. The skin includes twoprimary layers, i.e. the epidermis and the dermis. The epidermis is theoutermost layer of the skin and presents a barrier to deter the entry ofUV radiation, germs, heat, cold, dirt and gases while deterring theegress of water, blood, minerals, vitamins, hormones and protein. Theepidermis is composed of a plurality of sub-layers including severallayers of stratified epithelial tissue. The basilar layer of theepidermis includes melanocytes and other epithelial cells. Melanin isproduced by the melanocytes and serves to protect the skin from harmfuleffects of ultraviolet radiation. Skin cells are continuously movingfrom the lower layers to the upper layers of the epidermis and aresloughed off after they reach the skin surface. The dermis is comprisedof dense, irregular connective tissue and contains blood vessels, sweatglands, sebaceous glands, nerves, collagen and elastin. Collagencontributes to the firmness of the skin, and elastin imparts flexibilityand durability to the skin. The potential outcome of increased collagenlevels in facial skin is a reduction of wrinkles with enhanced skinresilience and a more youthful appearance.

There is a great demand for methods or procedures to reduce the effectsof aging and/or environmental exposure in skin and, in particular,facial skin. Conventional techniques for removing facial wrinklesinclude cosmetic or plastic surgery, one technique being commonly knownas “skin resurfacing”. Cosmetic surgery has numerous drawbacks includinginvasiveness, trauma, scarring, pain, significant recovery times andhigh financial cost. Conventional, non-surgical techniques for removingfacial wrinkles involve destruction of the epidermis and/or dermis bylaser energy used to vaporize the tissue, chemical burns or peels,physical debridement using drills and blasting the skin with apressurized stream of beads. Such non-surgical techniques typicallydestroy the epidermis, resulting in temporary and possibly permanentimpairment of the skin. For example, patients may be left with variouspigmentation problems including blotchiness, a predominantly whitecomplexion and/or the inability to tan.

U.S. Pat. No. 5,743,904 to Edwards discloses RF ablation of bodystructures, including fatty tissues in the cheeks, jaw and near theeyes, via electrodes inserted in the tissue. U.S. Pat. No. 5,871,524 toKnowlton discloses the use of RF electrodes and an electrolytic solutionto create a reverse thermal gradient in the skin to effect partialdenaturation and shrinkage of collagen resulting in tightening of theskin. Ultrasound is alluded to as a possible source of radiant energy tocreate the reverse thermal gradient. The stimulation of collagen growthby delivery of energy into the superficial layers of the dermis has alsobeen recognized. Lasers having wavelengths that penetrate the epidermiswithout damage thereto and stimulate the dermis to create collagen arebeing developed and marketed.

It has not been previously recognized to thermally stimulate collagengrowth by delivery of focused ultrasound energy into superficial layersof the dermis, while avoiding damage to the epidermis, in a minimallyinvasive, non-traumatic procedure not requiring physical penetration orwounding of the skin and while confining thermal stimulation to aspecific target area or areas within the skin.

SUMMARY OF THE INVENTION

Accordingly, it is a primary object of the present invention to overcomethe various disadvantages of prior methods of skin rejuvenation.

It is also an object of the present invention to effect skinrejuvenation by using high intensity focused ultrasound to stimulatecollagen growth.

Another object of the present invention is to utilize high intensityfocused ultrasound to effect wrinkle reduction by increasing collagenlevels in skin.

It is also an object of the present invention to use high intensityfocused ultrasound to thermally stimulate collagen growth in skinwithout impairing the epidermis.

The present invention also has as an object to use high intensityfocused ultrasound to thermally stimulate superficial layers of thedermis to increase collagen growth without damaging the epidermis.

Still a further object of the present invention is to focus ultrasoundenergy within the skin to form an internal ablated tissue area beginninga predetermined distance beneath an external surface of the skin inorder to stimulate collagen production.

The present invention also has as an object to focus ultrasound energy,emitted by an ultrasound emitting member, within the skin to form aninternal ablated tissue area beginning a predetermined distance from anactive face of the ultrasound emitting member in order to stimulatecollagen production.

It is another object of the present invention to use high intensityfocused ultrasound to form an ablated tissue area in the skin to apredetermined depth so that deep layers of the skin are not damaged.

An additional object of the present invention is to focus ultrasoundenergy within the skin to form an ablated tissue area in the superficiallayer of the dermis but not the deep layer of the dermis.

Some of the advantages of the present invention are that varyingintensity levels of ultrasound energy can be delivered to the skin forvarying periods of time depending on desired ablative effect, theduration of ultrasound energy delivery or application to the skin neededto accomplish a desired stimulation may be relatively brief depending ondesired size for the lesions of the ablated tissue area and/or desiredthermal effect on the tissue, the transducer or other member used toemit the ultrasound energy may be stationary or may be movable in orderto scan a target area with focused ultrasound, a plurality of individualablated tissue areas can be formed in the skin with the ablated tissueareas being separate and discontinuous or being contacting, abutting,contiguous or overlapping to form a single continuous ablated tissuearea of desired size and/or shape, the ultrasound emitting member canremain stationary or can be moved along the skin to scan a target areawith focused ultrasound, the transducer or other member may be designedwith a focusing configuration designed to ensure that the lesions of theablated tissue area have a desired cross-sectional size, begin a desireddepth within the skin and have a desired depth, the superficial dermisis thermally damaged to stimulate collagen growth with minimal traumaand pain for the patient, the transducer or other member is positionedexternally adjacent or in contact with an external surface of the skinor is acoustically coupled with the skin to form an internal ablatedtissue area without damaging the external skin surface and, inparticular, the epidermis, no external wound is presented since theepidermis is preserved, and an ablated tissue area of definitive sizecan be repeatedly and consistently produced.

These and other objects, advantages and benefits are realized with thepresent invention as generally characterized in a method of skinrejuvenation or wrinkle reduction by thermal stimulation using highintensity focused ultrasound wherein an ultrasound emitting member ispositioned adjacent an external surface of the skin, and ultrasoundenergy is emitted from the ultrasound emitting member into the tissue ofthe skin. The ultrasound energy is focused within the skin at aplurality of focusing zones disposed beneath the external skin surfaceand contained in a target area coincident with or containing thesuperficial dermis. The focusing zones are spaced from one another and,due to focusing of the ultrasound energy at the focusing zones, theultrasound energy is of higher or greater intensity in the tissue at thefocusing zones than in the tissue surrounding the focusing zones. Thetissue of the skin is heated at the focusing zones by the focusedultrasound energy, thereby forming an ablated tissue area below theexternal skin surface containing unablated skin tissue and a pluralityof lesions at the focusing zones, respectively, at which the tissue ofthe skin is ablated. Once an ablated tissue area of desired extent hasbeen obtained in the skin, the ultrasound emitting member is removed. Inreaction to the lesions, natural production of collagen in the dermis isstimulated. Collagen levels in the skin are thusly increased, resultingin a reduction of wrinkles and enhanced skin resilience for a moreyouthful appearance.

The ultrasound emitting member has a focusing configuration causing theultrasound energy to be focused a predetermined distance from an activeface of the ultrasound emitting member and, therefore, from the externalsurface of the skin, so that the epidermis is undamaged and preserved.Also, the focusing configuration results in formation of lesions ofpredetermined or known depth in accordance with the length of thefocusing zones, the selected ultrasound energy intensities and theselected duration times for ultrasound energy delivery. The lesiondepths are selected so that the lesions do not extend deeper thandesired in the skin, thereby avoiding damage to the deep layer of thedermis. The plurality of lesions may be non-contacting, with each lesionsurrounded by unablated skin tissue. One or more of the plurality oflesions may contact another one of the plurality of lesions. Thecross-sectional size of the lesions and the location and arrangement ofthe focusing zones in the skin result in formation of a specific sizeablated tissue area having a specific cross-sectional configuration. Asingle, discrete ablated tissue area or a plurality of single, discreteablated tissue areas can be formed in the skin in a single procedure ortreatment performed at one time or in multiple procedures or treatmentsperformed at different times. Where a plurality of ablated tissue areasare formed, the ablated tissue areas can be contiguous, contacting,overlapping or in abutment with one another so that the ablated tissueareas together form or create a single ablated tissue area of largercross-sectional size and/or of a desired cross-sectional configuration.

Other objects and advantages of the present invention will becomeapparent from the following description of the preferred embodimentstaken in conjunction with the accompanying drawings, wherein like partsin each of the several figures are identified by the same referencecharacters.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a broken perspective view, partly schematic, illustrating ahigh intensity focused ultrasound stimulation or ablation assembly foruse in the methods of the present invention.

FIG. 2 is a broken bottom view of an ultrasound emitting member of afocused ultrasound ablation device of the high intensity focusedultrasound stimulation or ablation assembly.

FIG. 3 is a broken side view, partly in section, of the ultrasoundemitting member and depicting focusing of ultrasound energy in the skinto form an ablated tissue area containing unablated skin tissue and aplurality of lesions at which the skin tissue is ablated.

FIG. 4 is a broken top view illustrating the surface or cross-sectionalconfiguration of the ablated tissue area of FIG. 3.

FIG. 5 is a broken top view illustrating the surface or cross-sectionalconfiguration of an alternative ablated tissue area created in the skin.

FIG. 6 is a broken top view illustrating the surface or cross-sectionalconfiguration of a plurality of further alternative ablated tissue areascreated in the skin.

FIG. 7 is a broken top view illustrating the surface or cross-sectionalconfiguration of another alternative ablated tissue area created in theskin.

FIG. 8 is a broken bottom view of an alternative focused ultrasoundablation device having a modified ultrasound emitting member for use inthe methods of the present invention.

FIG. 9 is a broken top view illustrating the surface or cross-sectionalconfiguration of an additional alternative ablated tissue area formed inthe skin.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A high intensity focused ultrasound ablation or stimulation assembly orsystem 10 for use in the methods of the present invention is illustratedin FIG. 1 and is similar to the high intensity focused ultrasoundstimulation assembly described in parent U.S. patent application Ser.No. 09/487,705 now abandoned and prior U.S. patent application Ser. No.09/487,710, the disclosures of which are incorporated herein byreference. The high intensity focused ultrasound ablation or stimulationassembly 10 includes a focused ultrasound ablation or stimulation device12, a power supply 14 and a controller 16. The focused ultrasoundablation or stimulation device 12 is similar to that described in U.S.patent applications Ser. Nos. 09/487,705 now abandoned and 09/487,710and includes a focused ultrasound emitting member 18, an elongate handleshaft or body 20 having a distal end at which the ultrasound emittingmember is disposed and a handle or handpiece 22 coupled to a proximalend of the handle shaft 20. As shown in FIGS. 2 and 3, the ultrasoundemitting member includes a transducer 24 carried by or within a housing,carrier or case 26. The transducer, which includes one or moreindividual ultrasound emitting elements or transducer elements, iscapable of generating and emitting ultrasound energy in response tobeing supplied with electrical power from power supply 14. In the caseof ultrasound emitting member 18, the transducer includes a plurality ofindividual ultrasound emitting elements or transducer elements 28, eachincluding a piezoelectric element that vibrates to produce ultrasoundenergy when an electrical current or signal is supplied thereto. Thetransducer elements 28 have a focusing configuration or geometry thatresults in the ultrasound energy produced thereby being focused a fixeddistance from the ultrasound emitting member. The transducer elements 28have a partial spherical or concave configuration causing the ultrasoundenergy generated thereby to be focused, as shown by arrows in FIG. 3, atfocusing zones F, respectively.

The transducer elements 28 are arranged in an array on or in housing 26;and, therefore, the transducer 24 may be considered a multi-arraytransducer. In the case of ultrasound emitting member 18, the transducerelements are arranged in a planar array of three rows R and six columnsC, although the transducer elements can be arranged in any number ofrows and columns. In the case of focused ultrasound emitting member 18,each row R has an equal number of transducer elements, and each column Chas an equal number of transducer elements. It should be appreciatedthat any number of transducer elements can be provided in each row andcolumn and that the number of transducer elements provided in each rowand column can be the same or different.

The transducer elements 28 can be referenced by their location in thearray. For example, the transducer element 28′ in the first row, firstcolumn can be designated transducer element R1C1, the transducer element28″ in the first row, second column can be designated transducer elementR1C2 and so on. The transducer elements may be disposed as close aspossible to one another; however, it should be appreciated that thespacing between the individual transducer elements 28 of the array canvary so that adjacent transducer elements can be disposed closertogether or further apart from one another. As explained further below,the transducer elements 28 are selectively, independently actuatable toselectively emit or not emit ultrasound energy.

The transducer elements 28 can be designed in various ways as known inthe art. In the case of transducer 24, the transducer elements eachcomprise a piezoelectric element formed by a layer of piezoelectricmaterial carried by housing 26. The piezoelectric elements are recessedfrom a planar external lower or bottom surface 32 of housing 26. Thepiezoelectric elements are curved in a direction inwardly of surface 32such that ultrasound energy generated by the piezoelectric elements isemitted from focused ultrasound emitting member 18 in a directionperpendicular to surface 32 for focusing at the focusing zones F, whichare spaced outwardly of surface 32. Accordingly, surface 32 is an activesurface or face of the ultrasound emitting member which, when positionedexternally on, adjacent or in contact with skin S, results in theultrasound energy emitted by the transducer being focused at zones F,which will be disposed within the skin S as shown in FIG. 3. When theultrasound emitting member is positioned on, against or adjacent theskin S at a location aligned with a designated target area 34 within theskin S, the target area 34 being shown in dotted lines in FIGS. 3 and 4,the focusing zones will be disposed at or within the target area as bestshown in FIG. 3.

Each focusing zone F consists of a single point or a plurality of pointsforming a zone at which the ultrasound energy is focused. Each focusingzone is in line with a central axis of the corresponding transducerelement. Each focusing zone is disposed a fixed predetermined distancefrom a plane containing the active face 32, the predetermined distancefor each focusing zone being perpendicular or normal to the active face32. Therefore, the focusing zones F will also be disposed apredetermined perpendicular distance or a calculable or determinableperpendicular distance from an external surface 36 of skin S with whichthe active face 32 is placed in contact or adjacent thereto. Where theactive face 32 is placed in contact with the external skin surface 36,the perpendicular distance that zones F are disposed from external skinsurface 36 will be the same as the predetermined distance. Where theactive face 32 is not placed in contact with the external skin surface36 but, rather, is spaced from the external skin surface 36 by a knownamount, for example, the perpendicular distance that zones F aredisposed from the external skin surface will correspond to thepredetermined distance minus the distance that the active face 32 isspaced from the external skin surface 36. Where the active face 32 isspaced from the external skin surface 36, an acoustic coupling mediumcan be disposed between the external skin surface 36 and the member 18.

Since the ultrasound is focused at focusing zones F, which are spacedfrom one another, the ultrasound is of greater or higher intensity atfocusing zones F than in tissue surrounding the focusing zones F.Ultrasound energy is thusly focused or concentrated at the focusingzones F, causing the skin at the focusing zones F to be heated to anablative temperature resulting in formation of lesions 38 at thefocusing zones, respectively. The tissue is ablated at the lesions 38;and, as used herein, “ablated” tissue includes tissue that has beenthermally damaged, altered, necrotized, denatured, destroyed, coagulatedor cauterized. When all of the transducer elements 28 are actuated, asshown in FIG. 3, heating of skin S will occur at a focusing zone F foreach transducer element, resulting in formation of a lesion 38 at eachfocusing zone F. The cross-sectional size of the lesions will normallydepend on the width of the focusing zones. However, depending on theintensity and duration of the ultrasound energy, the lesions 38 may“grow” or “spread” somewhat beyond the focusing zones due to thermalconduction causing the dispersal or spread of heat from the focusingzones. Therefore, depending on procedural parameters and the dimensionsof the focusing zones, each lesion 38 has a predetermined or predictablecross-sectional size, i.e. length and width, as well as depth. As anexample, each lesion 38 spreads radially outwardly somewhat from thecorresponding focusing zone. The lesions 38 have a generally circularsurface or cross-sectional configuration as shown in FIGS. 3 and 4 and aspecific depth as shown in FIG. 3. Depending on procedural parameters,the dimensions of the focusing zones and/or the type of tissue beingablated, the lesions may or may not have a uniform cross-section alongtheir depth. Where the focusing zones are sufficiently close together,and where the intensity of the ultrasound energy emitted from thetransducer elements is sufficiently high and is applied to the tissuefor a sufficient duration, the individual lesions may merge to form asingle continuous lesion at the target area so that the target area isfilled with ablated tissue. However, depending on the spacing betweenthe focusing zones, and depending on the intensity of the ultrasoundenergy emitted from the transducer elements and the duration ofultrasound energy delivery to the tissue, the lesions 38 may remainseparate, discrete and not connected to one another as shown in FIGS. 3and 4 so that the target area 34 contains unablated skin tissue and thelesions 38 at which the tissue of the skin is ablated. FIG. 4illustrates a lesion 38 formed in skin S for each focusing zone Fwherein the lesions 38 are disposed within the target area 34 but do notmerge with, contact, overlap or abut one another. Rather, each lesion 38is surrounded or circumscribed perimetrically by unablated skin tissue.The non-contacting lesions 38 and unablated skin tissue are contained inan ablated tissue area 35 at, coincident, coextensive or aligned withthe target area 34.

When all of the transducer elements 28 are actuated, an ablated tissuearea of specific surface or cross-sectional configuration and size iscreated within the skin S for the transducer 24 in accordance with theconfiguration and size of the array, the intensity level of the emittedultrasound energy, the duration or time of ultrasound energy delivery tothe skin, and the size of the lesions. Accordingly, an ablated tissuearea having a specific cross-sectional length, width and depth is formedin the skin, with the perimeter of the ablated tissue areacircumscribing the array of lesions 38. FIGS. 3 and 4 illustrate, indotted lines, the ablated tissue area 35 formed in skin S when all ofthe transducer elements are actuated. The ablated tissue area 35 has agenerally rectangular surface or cross-sectional configuration or areawith a predetermined cross-sectional length and width shown in FIG. 4and a predetermined cross-sectional depth, shown in FIG. 3, thecross-sectional depth corresponding to the depth of the lesions 38. Whenthe ultrasound emitting member 18 is positioned on, against or adjacentthe skin S at a location aligned with a designated target area 34 in theskin, the ablated tissue area 35 will be formed at or coincide with thetarget area as shown in FIGS. 3 and 4. The ablated tissue area issurrounded, bordered or circumscribed perimetrically by unablated skintissue, as well as having unablated skin tissue above and below it.Since the focusing zones F begin the predetermined distance or thecalculable or determinable distance below the external skin surface 36,the ablated tissue area 35 is an internal or subsurface ablated tissuearea beginning the predetermined distance or the calculable ordeterminable distance beneath the external skin surface. Accordingly,the lesions 38 and ablated tissue area 35 begin at a beginning orstarting margin 64 located the predetermined or calculable distancebelow the external tissue surface 36 and end at an ending margin 66disposed further below the external tissue surface than the beginningmargin, the distance between the beginning and ending marginscorresponding to the depth of the lesions 38 and, therefore, the depthof the ablated tissue area 35.

The housing 26 can have various external configurations and sizes andcan be formed by a portion of the transducer or can mount the transducerelements in various ways. The handle shaft 20 comprises an elongate,hollow or tubular member of sufficient length to position the ultrasoundemitting member 18 at various operative sites in or on the body of apatient while the handle 22 is maintained at a remote location,typically externally of the patient's body. The handle shaft 20 could besolid and may comprise a bar or other shaped member. Preferably, thehandle shaft 20 is malleable as disclosed in U.S. patent applicationSer. No. 09/488,844 now U.S. Pat. No. 6,361,531 issued Mar. 26, 2002,the disclosure of which is incorporated herein by reference. The handle22 has a forward end coupled to the proximal end of handle shaft 20 andhas a rearward end. The handle 22 preferably has a configuration tofacilitate grasping by a surgeon or other operator. One or more controlsor switches 42 may be provided on handle 22 to effect operation of thefocused ultrasound ablation device.

One or more electrical transmission wires 44 is/are connected to thetransducer 24 and extend through the handle shaft 20 for connection withpower supply 14 in order to transmit or supply electric current from thepower supply to the transducer. The power supply may be disposed partlyor entirely in the handle, or may be provided separately as a console orunit coupled to the handle shaft or the handle via one or moreappropriate transmission wires, which may be the same or different fromthe one or more transmission wires 44. For example, an electrical cordof suitable length may be removably coupled between the handle 22 andthe power supply 14. The power supply 14 can be designed in various waysas a source or supply of electricity to activate or excite transducer 24to generate and emit ultrasound energy. For example, the power supplycan be designed to provide high frequency alternating electrical currentto the transducer via the one or more transmission wires. The powersupply may include an RF generator, with or without an amplifier,providing a constant current source. Electrical current provided by thepower supply is selectively discharged into all or selected ones of thepiezoelectric elements producing vibration of all or selected ones ofthe piezoelectric elements and, therefore, producing acoustic orultrasonic waves or energy. The power supply may be separate from thehandle but may be operated via controls 42 on the handle.

In the case of focused ultrasound ablation device 12, a transmissionwire 44 is provided for each piezoelectric element and, therefore, foreach transducer element. As shown in FIG. 3, each transmission wire 44is connected to its corresponding piezoelectric element and to the powersupply so that the transducer elements are individually driven by orsupplied with current from the power supply. The transmission wires 44are disposed in respective passages within the housing and may bedisposed within a sheath or sleeve 46 extending through shaft 20.However, the transmission wires can be disposed externally of thehousing and/or the shaft. The transmission wires 44 are connected toswitches (not shown), respectively, for controlling the supply ortransmission of current from the power supply 14 to the piezoelectricelements, respectively. The switches can be incorporated in theultrasound emitting member 18, the power supply 14 and/or the controller16.

The controller or control unit 16 controls the supply of power frompower supply 14 to transducer 24 so that the transducer can be driven todeliver various intensity levels of ultrasound energy for variousdurations, periods or lengths of time. In particular, the controller 16controls the supply of power from the power supply to the individualpiezoelectric elements so that the transducer elements can beindividually driven or actuated to emit ultrasound energy. Thecontroller, which may be designed as part of the power supply, willtypically include a control panel and display monitor, one or moreswitches for current control, an input mechanism such as a keyboard,and/or a microprocessor including memory, storage and data processingcapabilities for performing various functions. The controller is capableof selectively activating the switches for the transducer elements to“fire” or effect actuation of all or selected ones of the plurality oftransducer elements to emit ultrasound energy. For example, switches onthe controller 16 and/or the controller keyboard can be used toselectively couple and decouple the individual transducer elements 28with the electrical drive signal or current from the power supply 14.

Input to the controller 16 provided by the surgeon or other medicalpersonnel determines the transducer elements 28 to be actuated. Forexample, data entered via the controller keyboard is used to identifythe particular transducer elements to be actuated, the transducerelements being identified, for example, by their location or position inthe array as explained above. In this manner, the switches of selectedtransducer elements can be activated to permit transmission ofelectrical current from the power supply to the piezoelectric elementsof the selected transducer elements while the switches of othernon-selected transducer elements can remain deactivated to preventtransmission of electrical current thereto when the power supply isactuated or switched to an “on” mode. It should be appreciated thatvarious components and/or methodology can be incorporated in the device12, the power supply 14 and/or the controller 16 to permit selectiveactuation of selected ones of the transducer elements 28 and that suchcomponents and/or methodology would be within the purview of one skilledin the art.

Various transducers can be used in the methods of the present invention.The piezoelectric elements can be made of various piezoelectricmaterials such as PZT crystal materials, hard lead, zirconate/leadtitanium, piezoelectric ceramic, or lithium-niobate piezoceramicmaterial. The transducer elements can be of various sizes and can havevarious focusing geometries. The frequency ranges of the transducers canvary depending on clinical needs. Transducer frequencies may be in therange of 0.5 to 12 MHz and, more typically, in the range of 5 to 12 MHz.Preferably, the transducer frequency will allow thermal ablation of theskin to be effected in response to the application or delivery ofultrasound energy to the skin for a relatively short duration or lengthof time. In accordance with the present invention, the duration orlength of time for ultrasound energy delivery or application to the skinpreferably ranges from 2 to 60 seconds depending on desired lesion sizeand/or ablative effect.

In accordance with the methods of the present invention, high intensityfocused ultrasound is used to create an internal ablated tissue areawithin the skin containing unablated skin tissue and a plurality oflesions at which the tissue of the skin is ablated. In reaction to thelesions, collagen growth in the skin is stimulated. In this manner,collagen levels in the skin are increased resulting in a reduction ofwrinkles, enhanced skin resilience and a more youthful appearance.

The skin S, as shown in FIG. 3, includes an outer or external layer,known as the epidermis E, and an inner or internal layer, known as thedermis DE. The epidermis E is comprised of a plurality of sub-layersincluding several layers of stratified epithelial tissue and definesexternal skin surface 36. The epidermis E has a basilar layer includingmelanocytes, which produce melanin serving to protect the skin from theharmful effects of ultraviolet radiation. The dermis DE, or “true skin”,is comprised of connective tissue with a varying amount of elasticfibers and numerous blood vessels, lymphatics, nerves and hair folliclesH. The dermis DE includes a superficial layer, known as the superficialdermis or papillary layer L, and a deep layer, known as the deep dermisor reticular layer R. The superficial layer L may itself be consideredas comprising a plurality of superficial sub-layers forming thesuperficial dermis. The reticular layer R contains collagen C andelastin, which impart firmness, flexibility and durability to the skin.

As shown in FIG. 3, the ultrasound emitting member 18 is placed againstthe skin S of a patient to position the active face 32 in contact withthe external skin surface 36. The active face is placed at or on theskin surface 36 at a location aligned with a desired target area 34 inthe skin for creation of an ablated tissue area, such locationcorresponding to an area of the skin that is to be rejuvenated. Theshaft 20 may be grasped and manipulated, as necessary, to facilitatepositioning of the active face at the desired location on the externalskin surface. Typically, the ultrasound emitting member will be placedin contact with skin of the patient's face at a location where areduction in wrinkles is desired, such as the forehead, cheeks, and theareas around the mouth and eyes. Also, all or specific ones of thetransducer elements are selected for actuation or “firing” in accordancewith the desired size and configuration for the ablated tissue areaand/or the desired number of lesions to be contained in the ablatedtissue area. The ablation device 12 is programmed via the controller toeffect actuation or “firing” of the selected transducer elements whenelectric current or a signal is supplied to the transducer. Of course,selection and programming for actuation or “firing” of selectedtransducer elements can be perfomed prior to positioning of member 18 onthe skin surface.

Once the active face is positioned in contact with the skin S at thedesired location, the power supply is activated or switched to an “on”mode to transmit electrical energy to the previously selected transducerelements. In response thereto, the piezoelectric elements correspondingto the selected transducer elements vibrate and produce ultrasoundenergy, which is focused within the skin S at the corresponding focusingzones F. In the procedure of FIG. 3, all of the transducer elements are“fired” to emit ultrasound energy, causing the skin to be heated to anablative temperature at a focusing zone for each transducer element. Theskin S at the focusing zones is heated to a temperature in the range of60 to 90 degrees Celsius for the time required to achieve ablation orthermal damage in the skin. The focusing zones are contained in thetarget area 34, which is coincident with or disposed in the superficialdermis L and is thusly disposed between the epidermis E and the deepdermis R. The skin S is heated at the focusing zones to a sufficientlyhigh temperature so as to cause a plurality of subsurface or internallesions 38 to be simultaneously formed in the skin S and, in particular,in the superficial dermis L, while the ultrasound emitting member 18remains external of and does not physically penetrate the skin S.

Lesions 38 have a generally circular surface or cross-sectionalconfiguration as shown in FIGS. 3 and 4 and do not contact or touch oneanother. Lesions 38 contain ablated or damaged skin tissue while theskin tissue surrounding each lesion 38 is not heated to the ablative orthermally damaging temperature and, therefore, is unablated orundamaged. In this manner, eighteen discontinuous or non-contactingindividual lesions 38 are formed in the skin as represented in FIG. 4.Lesions 38 are contained in the internal ablated tissue area 35coincident with the target area 34, the ablated tissue area 35containing the lesions 38 and the unablated skin tissue between adjacentlesions 38. The lesions 38 have a cross-sectional length and width and adepth of known parameters depending on the size and focusing geometry ofthe transducer elements, the intensity of the ultrasound energy, thetemperature to which the skin is heated and the duration of ultrasoundenergy delivery or application to the skin.

Due to the predetermined distance and the known length for the focusingzones, the lesions 38 and, therefore, the ablated tissue area 35, beginat the beginning or starting margin 64 located a predetermined or knowndepth beneath or below the external skin surface 36 and end at theending margin 66 located a greater predetermined or known depth beneaththe external skin surface 36, the distance between the beginning andending margins corresponding to the depth of the lesions and, therefore,the depth of the ablated tissue area 35. By selecting the appropriatefocusing zone depth and treatment parameters, a desired thickness ordepth of unablated or undamaged skin tissue between the beginning margin64 and the external tissue surface 36 is disposed outside the ablatedtissue area. Preferably, the beginning margin is located 50 to 150micrometers below the external skin surface. In the method of FIGS. 3and 4, a layer of unablated skin tissue about 100 micrometers thick ismaintained between the external skin surface 36 and the beginning orstarting margin 64 of the lesions 38, thusly preserving the epidermis Eof the skin S. The lesions 38 have a depth of 50 to 150 micrometers and,preferably, a depth of about 100 micrometers, in the directionperpendicular to skin surface 36 such that the ablated tissue area andthe lesions terminate or end at the ending margin 66 disposed a depth ofabout 200 micrometers beneath the external skin surface 36 at thetransducer/tissue interface. Accordingly, there is a perpendiculardistance of about 200 micrometers from the external skin surface to theending margin of the ablated tissue area such that the deep dermis R isundamaged and preserved. By selecting the appropriate focusing zonelength and treatment parameters, the depth of the ending margin 66within the skin is controlled thusly ensuring that the ablated tissuearea and lesions do not extend or extend only an insignificant amountinto the deep dermis.

As shown in FIG. 4, the ablated tissue area 35, which is surroundedabove, below and perimetrically by unablated or undamaged skin tissue,has a surface or cross-sectional configuration or area of generallyrectangular shape with a cross-sectional width and length varying from 3mm to 50 mm in either dimension, i.e. 3 mm×3 mm to 50 mm×50 mm or inbetween, depending on the size of the area to be treated. Although thecross-sectional length and width or other external dimensions of theablated tissue area can be determined by the locations of the “fired”transducer elements, it should be appreciated that the cross-sectionallength and/or width of the ablated tissue area can alternatively beobtained by moving the member 18 along the skin as described in U.S.patent application Ser. No. 09/487,705, the disclosure of which isincorporated herein by reference.

Depending on the desired lesion size and/or thermal effect, ultrasoundenergy will be delivered or applied to the skin for a duration in therange of 2 to 60 seconds. The emission of ultrasound energy byultrasound emitting member 18 is terminated by the surgeon or otheroperator once lesions of desired size or a desired amount of tissueablation has been obtained, and the member 18 is removed from thepatient's skin. In order to terminate the emission of ultrasound energyby the ultrasound emitting member, the power supply is deactivated orswitched to an “off” mode so that electrical current is no longersupplied to the selected piezoelectric elements.

The lesions 38, which typically contain thermally damaged tissue, causethe dermis DE to be stimulated to produce collagen C in the vicinity ofthe lesions. The lesions 38 are naturally assimilated or degraded andabsorbed by the patient's body and are replaced by healthy skin tissue.Accordingly, the level of collagen in the patient's skin increases inthe vicinity of the lesions resulting in a reduction of wrinkles,greater resiliency and a more youthful appearance.

FIG. 5 is representative of a single treatment procedure in accordancewith the present invention wherein a subsurface ablated tissue area 135containing four non-contacting lesions 138 is formed in the skin S. Theablated tissue area 135 is similar to ablated tissue area 35 except thatit is of generally square surface or cross-sectional configuration orarea and contains four generally circular lesions 138 each surrounded byunablated skin tissue. The ablated tissue area 135 can be formed usingthe ultrasound emitting member 18 by selecting and “firing” transducerelements R1C1, R1C2, R2C1 and R2C2, for example, to emit ultrasoundenergy. As described for the procedure illustrated in FIGS. 3 and 4, theultrasound energy emitted by the selectively “fired” or actuatedtransducer elements is focused in the skin at a focusing zone for eachactuated transducer element, causing subsurface lesions 138 to be formedin the skin at the focusing zones corresponding to transducer elementsR1C1, R1C2, R2C1 and R2C2. The lesions 138 are similar to lesions 38 butare larger in diametric cross-sectional size than lesions 38. Theablated tissue area 135 is surrounded by unablated tissue above, belowand perimetrically.

FIG. 6 is representative of a multiple treatment procedure in accordancewith the present invention wherein a plurality of internal ablatedtissue areas 235, each containing unablated skin tissue and a pluralityof lesions 238, are formed or created in the skin S. The ablated tissueareas 235 are spaced from one another, and each contains two generallycircular lesions 238 similar to lesions 138 except that lesions 238 havea slightly larger cross-sectional diameter than lesions 138. The lesions238 of each ablated tissue area 235 are spaced slightly from one anotherand are surrounded by unablated skin tissue so as to be non-contacting.Each ablated tissue area 235 has a surface or cross-sectionalconfiguration or area of generally rectangular shape. The ablated tissueareas 235, which are similar to ablated tissue area 35 except for theircross-sectional configuration, can be formed using member 18 asdescribed above by actuating an appropriate pair of transducer elements.The ablated tissue areas 235 are typically formed in separate treatmentsperformed at different times. However, it should be appreciated that aplurality of ablated tissue areas, such as ablated tissue areas 235, canbe formed in the skin during a single procedure performed at one time.

FIG. 7 illustrates in dotted lines an ablated tissue area 335 ofrectangular cross-sectional configuration formed in the skin S andcontaining six generally circular non-contacting lesions 338 eachsurrounded by unablated tissue. The lesions 338 and ablated tissue area335 are similar to the lesions 38 and ablated tissue area 35 except forthe cross-sectional size of lesions 338 being different from thecross-sectional size of lesions 38. The ablated tissue area 335 willtypically be formed in a single treatment or procedure. The ablatedtissue area 335 can be formed using the ultrasound emitting member 18 byactuating six appropriate transducer elements.

It should be appreciated that the methods of skin rejuvenation accordingto the present invention can be performed using focused ultrasoundablation devices wherein the transducer elements of the ultrasoundemitting members are not selectively actuatable. For example, FIG. 8illustrates an alternative focused ultrasound ablation device 412 havingfocused ultrasound emitting member 418, which is similar to focusedultrasound emitting member 18 except that focused ultrasound emittingmember 418 includes an array of six transducer elements 428 actuatablesimultaneously or in unison to emit ultrasound energy. The transducerelements 428 are arranged in two rows and three columns and are used toform an ablated tissue area containing six lesions, such as ablatedtissue area 335. Accordingly, it should be appreciated that variousdedicated ultrasound emitting members having different arrays and/ornumbers of transducer elements can be provided, with a particularultrasound emitting member being capable of obtaining a particularablated tissue area of predetermined size, configuration and number oflesions in response to actuation of all of the transducer elements ofthe particular ultrasound emitting member.

FIG. 9 illustrates an alternative, subsurface ablated tissue area 535formed in the skin S in a manner similar to ablated tissue area 135.However, the ultrasound energy used to form ablated tissue area 535 isof higher intensity and/or is applied to the skin for a longer durationthan the ultrasound energy used to form ablated tissue area 135.Accordingly, the lesions 538 of ablated tissue area 535 have a generallycircular surface or cross-sectional configuration larger in diameterthan the generally circular cross-sectional configuration of lesions 138due to greater dispersal of heat from the focusing zones. As a result,the lesions 538 contact or touch one another but still do not mergesufficiently to fill the entire ablated tissue area 535 with ablatedtissue. Although each lesion 538 is not completely surroundedperimetrically by unablated tissue, there is still some unablated tissuewithin the ablated tissue area 535 as shown in FIG. 9 by unablated skintissue disposed between adjacent lesions 538. It should be appreciated,therefore, that the ablated tissue areas formed in accordance with thepresent invention can include a plurality of non-contacting lesions eachcompletely surrounded by unablated tissue and/or a plurality ofcontacting lesions with unablated tissue between the contacting lesions.

In the procedures described and illustrated above, the ultrasoundemitting member is placed against the skin at a desired location to forman ablated tissue area of final size and configuration in the skin withfocused ultrasound energy generated and emitted by the ultrasoundemitting member without moving the ultrasound emitting member from thedesired location. It should be appreciated, however, that where thelargest size ablated tissue area capable of being formed in the skinwith the ultrasound emitting member is smaller than the final sizeand/or different from the final configuration desired for the ablatedtissue area, the ultrasound emitting member can be moved along the skinto form an ablated tissue area of desired final size and configurationas explained in U.S. patent application Ser. No. 09/487,705 nowabandoned.

The methods of the present invention allow skin rejuvenation to beperformed with minimal trauma and pain for the patient and with fasterhealing and recovery times. The epidermis is preserved so that noexternal wound is presented or exposed. A single treatment in accordancewith the present invention may be sufficient to reduce wrinkles in adesired area since an ablated tissue area of sufficient size may beobtained with a single treatment. By controlling the delivery ofultrasound energy to the skin, the temperature to which the skin isheated by the ultrasound energy can be controlled to avoid undesiredpatient responses. The ultrasound emitting members can be provided withsensors for monitoring the amount of ultrasound energy delivered to theskin and/or for detecting the temperature to which the skin is heated,which can be provided as feedback to the controller. The delivery ofultrasound energy to the skin can be controlled to achieve a selectedtemperature in the skin, a selected amount of ablation, a desired lesionsize or a desired duration of ultrasonic energy delivery. The ultrasoundemitting members can be disposable or can be designed to be reusable andthusly can be capable of being sterilized to medical standards. Theultrasound emitting members can be provided with disposable covers orguards which can be removed and discarded after use so that theultrasound emitting members can be reused. The transducer or transducerelements can be removable from the ultrasound emitting members allowingdisposability of the ultrasound emitting members and reuse of thetransducer or transducer elements in another ultrasound emitting member.The ultrasound emitting members can be immobilized during use as may beaccomplished with various types of stabilizing members provided on theshafts or on the ultrasound emitting members. The focused ultrasoundablation devices can be provided with imaging capabilities or can beused with various imaging devices as disclosed in U.S. patentapplication Ser. No. 09/487,705 now abandoned. The focused ultrasoundablation devices can be provided with cooling systems for cooling theultrasound emitting members and/or the transducers as disclosed in U.S.patent application Ser. No. 09/487,705 now abandoned. The methods ofskin rejuvenation can be performed using an acoustic coupling medium asdisclosed in U.S. patent application Ser. No. 09/487,705 now abandoned.A single ultrasound emitting member can be used to form variousdifferent ablated tissue areas of various sizes, configurations, andnumber of lesions depending on the particular transducer elementsselected for actuation. A plurality of different ultrasound emittingmembers having non-selectively actuatable transducer elements can beprovided with each ultrasound emitting member having a different arrayand/or number of transducer elements to obtain a particular ablatedtissue area of predetermined size, configuration and number of lesionswhen all of the transducer elements of the ultrasound emitting membersare actuated. Any number of ablated tissue areas can be formed in theskin with each ablated tissue area surrounded by unablated tissue orwith the ablated tissue areas contiguous to, in abutment with,contacting or overlapping one another to form a single ablated tissuearea. The ultrasound emitting members, the transducers and/or thetransducer elements can be moved relative to the tissue to scan targetareas with focused ultrasound energy, and such scanning can beaccomplished in various diverse ways. The ablated tissue areas caninclude unablated tissue and a plurality of non-contacting lesions, aplurality of contacting lesions or a combination of contacting andnon-contacting lesions. Any number of lesions can be contained in theablated tissue areas including even and odd numbers of lesions.

Inasmuch as the present invention is subject to many variations,modifications and changes in detail, it is intended that all subjectmatter discussed above or shown in the accompanying drawings beinterpreted as illustrative only and not be taken in a limiting sense.

What is claimed is:
 1. A method of skin rejuvenation comprising thesteps of positioning an ultrasound emitting member adjacent an externaltissue surface of the skin of a patient; emitting ultrasound energy fromthe ultrasound emitting member into the skin; focusing the ultrasoundenergy simultaneously at a plurality of spaced focusing zones containedin a target area in the skin; heating the skin at the focusing zoneswith the focused ultrasound energy to form an ablated tissue area at thetarget area containing unablated tissue of the skin and a plurality oflesions at the focusing zones, respectively, at which the tissue of theskin is ablated; and removing the ultrasound emitting member fromadjacent the external surface of the skin.
 2. The method of skinrejuvenation as recited in claim 1 wherein said step of focusingincludes focusing the ultrasound energy in a target area disposedbeneath the external surface of the skin.
 3. The method of skinrejuvenation as recited in claim 2 wherein said step of heating includesheating the skin at the focusing zones with the focused ultrasoundenergy to achieve a temperature in the range of 60 to 90 degreesCelsius.
 4. The method of skin rejuvenation as recited in claim 3wherein said step of heating includes heating the skin at the focusingzones with the focused ultrasound energy so that the lesions begin at abeginning margin located below the epidermis of the skin.
 5. The methodof skin rejuvenation as recited in claim 4 wherein said step of heatingincludes heating the skin at the focusing zones with the focusedultrasound energy so that the lesions end at an ending margin locatedabove the deep dermis of the skin.
 6. The method of skin rejuvenation asrecited in claim 5 wherein said step of heating includes heating theskin at the focusing zones with the focused ultrasound energy for aduration in the range of 2 to 60 seconds.
 7. The method of skinrejuvenation as recited in claim 1 wherein said step of heating includesforming the ablated tissue area surrounded by unablated tissue of theskin.
 8. The method of skin rejuvenation as recited in claim 7 whereinsaid step of heating includes forming the ablated tissue area so thatthe plurality of lesions do not contact one another.
 9. The method ofskin rejuvenation as recited in claim 7 wherein said step of heatingincludes forming the ablated tissue area so that at least one of theplurality of lesions contacts another of the plurality of lesions.
 10. Amethod of skin rejuvenation comprising the steps of positioning anultrasound emitting member adjacent an external surface of the skin;emitting ultrasound energy simultaneously from a plurality of ultrasoundemitting elements of the ultrasound emitting member; focusing theultrasound energy in the skin below the external surface of the skin ata plurality of spaced focusing zones corresponding to the ultrasoundemitting elements, respectively, while the ultrasound emitting member ismaintained in one place adjacent the external surface of the skin;ablating the skin with the focused ultrasound energy to form an ablatedtissue area below the external surface of the skin containing unablatedtissue of the skin and a plurality of lesions at the focusing zones,respectively, at which the tissue of the skin is ablated, the reactionto which is production of collagen by the dermis; and removing theultrasound emitting member from adjacent the external surface of theskin.
 11. The method of skin rejuvenation as recited in claim 10 whereinsaid step of ablating includes forming the plurality of lesions to beginat a beginning margin located 50 to 100 micrometers below the externalsurface of the skin.
 12. The method of skin rejuvenation as recited inclaim 11 wherein said step of ablating includes forming the plurality oflesions to have a depth of 50 to 150 micrometers.
 13. The method of skinrejuvenation as recited in claim 12 wherein said step of ablatingincludes forming the ablated tissue area to have a cross-sectionallength of 3 to 50 mm and a cross-sectional width of 3 to 50 mm.
 14. Themethod of skin rejuvenation as recited in claim 10 wherein said step offocusing includes focusing the ultrasound energy in the superficialdermis of the skin.
 15. A method of skin rejuvenation comprising thesteps of positioning an ultrasound emitting member adjacent an externalsurface of the skin of a patient; actuating selected ones of a pluralityof ultrasound emitting elements of the ultrasound emitting member toemit ultrasound energy; simultaneously emitting ultrasound energy fromthe selected ultrasound emitting elements into the skin; focusing theultrasound energy in the skin below the epidermis simultaneously at aplurality of spaced focusing zones corresponding to the selectedultrasound emitting elements, respectively; ablating the skin with thefocused ultrasound energy to form an ablated tissue area below theepidermis containing unablated tissue of the skin and a plurality oflesions at the focusing zones, respectively, at which the tissue of theskin is ablated; and removing the ultrasound emitting member fromadjacent the external surface of the skin.
 16. The method of skinrejuvenation as recited in claim 15 and further including, prior to saidstep of actuating, the step of selecting the ultrasound emittingelements to be actuated in accordance with a desired surface pattern forthe plurality of lesions.
 17. The method of skin rejuvenation as recitedin claim 16 wherein said step of ablating includes forming the ablatedtissue area between the epidermis and deep dermis of the skin.
 18. Themethod of skin rejuvenation as recited in claim 15 and furtherincluding, subsequent to said step of removing, the step of allowing theplurality of lesions to be assimilated by the patient's body whereby theproduction of collagen by the skin is increased in the ablated tissuearea.